Medical research has demonstrated that light can be used to treat a variety of disorders. Typical references showing the use of light to treat such disorders are in the following publications, which are illustrative of a number of such publications:
Czeisler, C. A., Allan J. S., Strogatz, S. H., Ronda, J. M., Sanchez, R., Rios, D., Freitag, W., O., Richardson, G. S., & Kronauer, R. E. (1986). Bright lights resets the human circadian pacemaker independent of the timing of the sleep-wake cycle. Science 233:667-671. PA0 Lewy, A. J., Wehr, T. A., Goodwin, F. K., Newsome, D. A., & Markey, S. P. (1980) Light suppresses melatonin secretion in humans. Science 210:1267-1269. PA0 Neer, R. M. (1985) Environmental light: effects of Vitamin D synthesis and calcium metabolism in humans. Annals of the New York Academy of Sciences 453:14-20. PA0 Rosenthal, N. E., Sack, D. A., Gillin, J. D., Lewy, A. J., et al. (1984) Seasonal affective disorder: A description of the syndrome and preliminary findings with light therapy. Archives of General Psychiatry 41:72-80. PA0 Terman, M., Terman, J. S., Quitkin, F. M., McGrath, P. J., & Stewart, J. W. (1987) Light therapy for Seasonal Affective Disorder: A review of efficacy. PA0 Wirz-Justice, A., Bucheli, C., Graw, P., Kielholz, P., et al (1986) Light treatment of seasonal effective disorder in Switzerland. Acta Psychiatrica Scandinavica 74:193-204.
In summary, the above publications and others show that light has been and can be used to treat seasonal affective disorder (SAD), adjust the circadian rhythm, enhance mood, decrease fatigue, treat jet lag, etc.
In the past, the light has been administered by using banks of fluorescent lamps grouped together to produce light intensities in the range of from about 2,000 to about 10,000 lux. Units for producing high intensity light in the range of from about 7,000 to 10,000 lux or more have been demonstrated to be effective in carrying out the necessary phototherapy treatment over much shorter time periods than where the light intensity is in the lower range say about 2,000-3,000 lux. In either prior method of treatment, the light units were of the type using fluorescent lamp tubes of standard length, e.g., 24" through 92", and the user sits two-three feet from the unit to receive the necessary light intensity. Consequently, his movement is restricted.